Texas Rangers pitcher Matt Harrison is encouraged by how his back feels, but does not expect to be ready for the first series of the regular season against the Philadelphia Phillies.

"I'm probably 10 days behind," Harrison said. "Hopefully, I can get back for the second or third series of the year."

Harrison blames the tightness he felt earlier in the week on a soft bed. He slept on the floor one night and is now on a firmer bed and said his back feels good.

That won't stop Harrison from flying back to Texas on Sunday and getting checked out by back specialist Dr. Drew Dossett, who handled both of the left-hander's back surgeries last year.

The Rangers and Harrison want to be completely sure that it is what Harrison thinks it is -- tightness that has gone away -- and not anything more.

"We want these guys to be strong at the end of the season," Rangers assistant general manager Thad Levine said. "Starts in September and October are definitely more valued in our minds than starts in April. We want to make sure they're healthy for the stretch drive."

Harrison felt tightness in his back on Wednesday. But by Friday, he was feeling better after sleeping on the floor. He is now in a firmer bed and has not had issues for the past few days. But he's been shut down from baseball activity.